/*
* Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package java.lang;
import java.lang.annotation.Annotation;
import java.lang.reflect.AnnotatedElement;
import java.lang.reflect.Module;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URL;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Objects;
import jdk.internal.loader.BootLoader;
import jdk.internal.reflect.CallerSensitive;
import jdk.internal.reflect.Reflection;
/**
* Represents metadata about a run-time package associated with a class loader.
* Metadata includes annotations, versioning, and sealing.
* <p>
* Annotations for the run-time package are read from {@code package-info.class}
* at the same code source as classes in the run-time package.
* <p>
* The set of classes that make up the run-time package may implement a
* particular specification. The specification title, version, and vendor
* (indicating the owner/maintainer of the specification) can be provided
* when the {@code Package} is defined. An application can ask if the
* {@code Package} is compatible with a particular specification version
* by using the {@link #isCompatibleWith Package.isCompatibleWith(String)}
* method. In addition, information about the actual classes that make up the
* run-time package can be provided when the Package is defined.
* This information consists of an implementation title, version, and vendor
* (indicating the supplier of the classes).
* <p>
* A {@code Package} may be explicitly defined with
* the {@link ClassLoader#definePackage(String, String, String, String,
* String, String, String, URL)} method.
* The caller supplies the specification and implementation titles, versions, and
* vendors. The caller also indicates whether the package is
* {@linkplain java.util.jar.Attributes.Name#SEALED sealed}.
* If a {@code Package} is not explicitly defined for a run-time package when
* a class in that run-time package is defined, then a {@code Package} is
* automatically defined by the class's defining class loader, as follows.
* <p>
* A {@code Package} automatically defined for classes in a named module has
* the following properties:
* <ul>
* <li>The name of the package is derived from the {@linkplain Class#getName() binary names}
* of the classes. Since classes in a named module must be in a named package,
* the derived name is never empty.</li>
* <li>The package is sealed with the {@linkplain java.lang.module.ModuleReference#location()
* module location} as the code source, if known.</li>
* <li>The specification and implementation titles, versions, and vendors
* are unspecified.</li>
* <li>Any annotations on the package are read from {@code package-info.class}
* as specified above.</li>
* </ul>
* <p>
* A {@code Package} automatically defined for classes in an unnamed module
* has the following properties:
* <ul>
* <li>The name of the package is either {@code ""} (for classes in an unnamed package)
* or derived from the {@linkplain Class#getName() binary names} of the classes
* (for classes in a named package).</li>
* <li>The package is not sealed.</li>
* <li>The specification and implementation titles, versions, and vendors
* are unspecified.</li>
* <li>Any annotations on the package are read from {@code package-info.class}
* as specified above.</li>
* </ul>
*
* <p>
* A {@code Package} can be obtained with the {@link Package#getPackage
* Package.getPackage(String)} and {@link ClassLoader#getDefinedPackage
* ClassLoader.getDefinedPackage(String)} methods.
* Every {@code Package} defined by a class loader can be obtained
* with the {@link Package#getPackages Package.getPackages()} and
* {@link ClassLoader#getDefinedPackages} methods.
*
* @jvms 5.3 Run-time package
* @see <a href="../../../technotes/guides/jar/jar.html#versioning">
* The JAR File Specification: Package Versioning</a>
* @see <a href="../../../technotes/guides/jar/jar.html#sealing">
* The JAR File Specification: Package Sealing</a>
* @see ClassLoader#definePackage(String, String, String, String, String, String, String, URL)
*
* @since 1.2
*/
public class Package extends NamedPackage implements java.lang.reflect.AnnotatedElement {
/**
* Return the name of this package.
*
* @return The fully-qualified name of this package as defined in section 6.5.3 of
* <cite>The Java™ Language Specification</cite>,
* for example, {@code java.lang}
*/
public String getName() {
return packageName();
}
/**
* Return the title of the specification that this package implements.
* @return the specification title, {@code null} is returned if it is not known.
*/
public String getSpecificationTitle() {
return versionInfo.specTitle;
}
/**
* Returns the version number of the specification
* that this package implements.
* This version string must be a sequence of non-negative decimal
* integers separated by "."'s and may have leading zeros.
* When version strings are compared the most significant
* numbers are compared.
*
*
* <p>Specification version numbers use a syntax that consists of non-negative
* decimal integers separated by periods ".", for example "2.0" or
* "1.2.3.4.5.6.7". This allows an extensible number to be used to represent
* major, minor, micro, etc. versions. The version specification is described
* by the following formal grammar:
* <blockquote>
* <dl>
* <dt><i>SpecificationVersion:</i>
* <dd><i>Digits RefinedVersion<sub>opt</sub></i>
* <dt><i>RefinedVersion:</i>
* <dd>{@code .} <i>Digits</i>
* <dd>{@code .} <i>Digits RefinedVersion</i>
*
* <dt><i>Digits:</i>
* <dd><i>Digit</i>
* <dd><i>Digits</i>
*
* <dt><i>Digit:</i>
* <dd>any character for which {@link Character#isDigit} returns {@code true},
* e.g. 0, 1, 2, ...
* </dl>
* </blockquote>
*
* @return the specification version, {@code null} is returned if it is not known.
*/
public String getSpecificationVersion() {
return versionInfo.specVersion;
}
/**
* Return the name of the organization, vendor,
* or company that owns and maintains the specification
* of the classes that implement this package.
* @return the specification vendor, {@code null} is returned if it is not known.
*/
public String getSpecificationVendor() {
return versionInfo.specVendor;
}
/**
* Return the title of this package.
* @return the title of the implementation, {@code null} is returned if it is not known.
*/
public String getImplementationTitle() {
return versionInfo.implTitle;
}
/**
* Return the version of this implementation. It consists of any string
* assigned by the vendor of this implementation and does
* not have any particular syntax specified or expected by the Java
* runtime. It may be compared for equality with other
* package version strings used for this implementation
* by this vendor for this package.
* @return the version of the implementation, {@code null} is returned if it is not known.
*/
public String getImplementationVersion() {
return versionInfo.implVersion;
}
/**
* Returns the vendor that implemented this package, {@code null}
* is returned if it is not known.
* @return the vendor that implemented this package, {@code null}
* is returned if it is not known.
*/
public String getImplementationVendor() {
return versionInfo.implVendor;
}
/**
* Returns true if this package is sealed.
*
* @return true if the package is sealed, false otherwise
*/
public boolean isSealed() {
return module().isNamed() || versionInfo.sealBase != null;
}
/**
* Returns true if this package is sealed with respect to the specified
* code source {@code url}.
*
* @param url the code source URL
* @return true if this package is sealed with respect to the given {@code url}
*/
public boolean isSealed(URL url) {
Objects.requireNonNull(url);
URL sealBase = null;
if (versionInfo != VersionInfo.NULL_VERSION_INFO) {
sealBase = versionInfo.sealBase;
} else {
try {
URI uri = location();
sealBase = uri != null ? uri.toURL() : null;
} catch (MalformedURLException e) {
}
}
return url.equals(sealBase);
}
/**
* Compare this package's specification version with a
* desired version. It returns true if
* this packages specification version number is greater than or equal
* to the desired version number. <p>
*
* Version numbers are compared by sequentially comparing corresponding
* components of the desired and specification strings.
* Each component is converted as a decimal integer and the values
* compared.
* If the specification value is greater than the desired
* value true is returned. If the value is less false is returned.
* If the values are equal the period is skipped and the next pair of
* components is compared.
*
* @param desired the version string of the desired version.
* @return true if this package's version number is greater
* than or equal to the desired version number
*
* @exception NumberFormatException if the current version is not known or
* the desired or current version is not of the correct dotted form.
*/
public boolean isCompatibleWith(String desired)
throws NumberFormatException
{
if (versionInfo.specVersion == null || versionInfo.specVersion.length() < 1) {
throw new NumberFormatException("Empty version string");
}
String [] sa = versionInfo.specVersion.split("\\.", -1);
int [] si = new int[sa.length];
for (int i = 0; i < sa.length; i++) {
si[i] = Integer.parseInt(sa[i]);
if (si[i] < 0)
throw NumberFormatException.forInputString("" + si[i]);
}
String [] da = desired.split("\\.", -1);
int [] di = new int[da.length];
for (int i = 0; i < da.length; i++) {
di[i] = Integer.parseInt(da[i]);
if (di[i] < 0)
throw NumberFormatException.forInputString("" + di[i]);
}
int len = Math.max(di.length, si.length);
for (int i = 0; i < len; i++) {
int d = (i < di.length ? di[i] : 0);
int s = (i < si.length ? si[i] : 0);
if (s < d)
return false;
if (s > d)
return true;
}
return true;
}
/**
* Finds a package by name in the caller's class loader and its
* ancestors.
* <p>
* If the caller's class loader defines a {@code Package} of the given name,
* the {@code Package} is returned. Otherwise, the ancestors of the
* caller's class loader are searched recursively (parent by parent)
* for a {@code Package} of the given name.
* <p>
* Calling this method is equivalent to calling {@link ClassLoader#getPackage}
* on a {@code ClassLoader} instance which is the caller's class loader.
*
* @param name A package name, such as "{@code java.lang}".
* @return The {@code Package} of the given name defined by the caller's
* class loader or its ancestors, or {@code null} if not found.
*
* @throws NullPointerException
* if {@code name} is {@code null}.
*
* @deprecated
* If multiple class loaders delegate to each other and define classes
* with the same package name, and one such loader relies on the lookup
* behavior of {@code getPackage} to return a {@code Package} from
* a parent loader, then the properties exposed by the {@code Package}
* may not be as expected in the rest of the program.
* For example, the {@code Package} will only expose annotations from the
* {@code package-info.class} file defined by the parent loader, even if
* annotations exist in a {@code package-info.class} file defined by
* a child loader. A more robust approach is to use the
* {@link ClassLoader#getDefinedPackage} method which returns
* a {@code Package} for the specified class loader.
*
* @see ClassLoader#getDefinedPackage
*/
@CallerSensitive
@Deprecated(since="9")
@SuppressWarnings("deprecation")
public static Package getPackage(String name) {
ClassLoader l = ClassLoader.getClassLoader(Reflection.getCallerClass());
return l != null ? l.getPackage(name) : BootLoader.getDefinedPackage(name);
}
/**
* Returns all of the {@code Package}s defined by the caller's class loader
* and its ancestors. The returned array may contain more than one
* {@code Package} object of the same package name, each defined by
* a different class loader in the class loader hierarchy.
* <p>
* Calling this method is equivalent to calling {@link ClassLoader#getPackages}
* on a {@code ClassLoader} instance which is the caller's class loader.
*
* @return The array of {@code Package} objects defined by this
* class loader and its ancestors
*
* @see ClassLoader#getDefinedPackages
*/
@CallerSensitive
public static Package[] getPackages() {
ClassLoader cl = ClassLoader.getClassLoader(Reflection.getCallerClass());
return cl != null ? cl.getPackages() : BootLoader.packages().toArray(Package[]::new);
}
/**
* Return the hash code computed from the package name.
* @return the hash code computed from the package name.
*/
@Override
public int hashCode(){
return packageName().hashCode();
}
/**
* Returns the string representation of this Package.
* Its value is the string "package " and the package name.
* If the package title is defined it is appended.
* If the package version is defined it is appended.
* @return the string representation of the package.
*/
@Override
public String toString() {
String spec = versionInfo.specTitle;
String ver = versionInfo.specVersion;
if (spec != null && spec.length() > 0)
spec = ", " + spec;
else
spec = "";
if (ver != null && ver.length() > 0)
ver = ", version " + ver;
else
ver = "";
return "package " + packageName() + spec + ver;
}
private Class<?> getPackageInfo() {
if (packageInfo == null) {
// find package-info.class defined by loader
String cn = packageName() + ".package-info";
Module module = module();
PrivilegedAction<ClassLoader> pa = module::getClassLoader;
ClassLoader loader = AccessController.doPrivileged(pa);
Class<?> c;
if (loader != null) {
c = loader.loadClass(module, cn);
} else {
c = BootLoader.loadClass(module, cn);
}
if (c != null) {
packageInfo = c;
} else {
// store a proxy for the package info that has no annotations
class PackageInfoProxy {}
packageInfo = PackageInfoProxy.class;
}
}
return packageInfo;
}
/**
* @throws NullPointerException {@inheritDoc}
* @since 1.5
*/
public <A extends Annotation> A getAnnotation(Class<A> annotationClass) {
return getPackageInfo().getAnnotation(annotationClass);
}
/**
* {@inheritDoc}
* @throws NullPointerException {@inheritDoc}
* @since 1.5
*/
@Override
public boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) {
return AnnotatedElement.super.isAnnotationPresent(annotationClass);
}
/**
* @throws NullPointerException {@inheritDoc}
* @since 1.8
*/
@Override
public <A extends Annotation> A[] getAnnotationsByType(Class<A> annotationClass) {
return getPackageInfo().getAnnotationsByType(annotationClass);
}
/**
* @since 1.5
*/
public Annotation[] getAnnotations() {
return getPackageInfo().getAnnotations();
}
/**
* @throws NullPointerException {@inheritDoc}
* @since 1.8
*/
@Override
public <A extends Annotation> A getDeclaredAnnotation(Class<A> annotationClass) {
return getPackageInfo().getDeclaredAnnotation(annotationClass);
}
/**
* @throws NullPointerException {@inheritDoc}
* @since 1.8
*/
@Override
public <A extends Annotation> A[] getDeclaredAnnotationsByType(Class<A> annotationClass) {
return getPackageInfo().getDeclaredAnnotationsByType(annotationClass);
}
/**
* @since 1.5
*/
public Annotation[] getDeclaredAnnotations() {
return getPackageInfo().getDeclaredAnnotations();
}
/**
* Construct a package instance for an unnamed module
* with the specified version information.
*
* @apiNote
* This method should not be called to define a Package for named module.
*
* @param name the name of the package
* @param spectitle the title of the specification
* @param specversion the version of the specification
* @param specvendor the organization that maintains the specification
* @param impltitle the title of the implementation
* @param implversion the version of the implementation
* @param implvendor the organization that maintains the implementation
* @param sealbase code source where this Package comes from
* @param loader defining class loader
*/
Package(String name,
String spectitle, String specversion, String specvendor,
String impltitle, String implversion, String implvendor,
URL sealbase, ClassLoader loader)
{
super(Objects.requireNonNull(name),
loader != null ? loader.getUnnamedModule()
: BootLoader.getUnnamedModule());
this.versionInfo = VersionInfo.getInstance(spectitle, specversion,
specvendor, impltitle,
implversion, implvendor,
sealbase);
}
Package(String name, Module module) {
super(name, module);
this.versionInfo = VersionInfo.NULL_VERSION_INFO;
}
/*
* Versioning information. Only for packages in unnamed modules.
*/
static class VersionInfo {
static final VersionInfo NULL_VERSION_INFO
= new VersionInfo(null, null, null, null, null, null, null);
private final String specTitle;
private final String specVersion;
private final String specVendor;
private final String implTitle;
private final String implVersion;
private final String implVendor;
private final URL sealBase;
static VersionInfo getInstance(String spectitle, String specversion,
String specvendor, String impltitle,
String implversion, String implvendor,
URL sealbase) {
if (spectitle == null && specversion == null &&
specvendor == null && impltitle == null &&
implvendor == null && sealbase == null) {
return NULL_VERSION_INFO;
}
return new VersionInfo(spectitle, specversion, specvendor,
impltitle, implversion, implvendor,
sealbase);
}
private VersionInfo(String spectitle, String specversion,
String specvendor, String impltitle,
String implversion, String implvendor,
URL sealbase)
{
this.implTitle = impltitle;
this.implVersion = implversion;
this.implVendor = implvendor;
this.specTitle = spectitle;
this.specVersion = specversion;
this.specVendor = specvendor;
this.sealBase = sealbase;
}
}
private final VersionInfo versionInfo;
private Class<?> packageInfo;
}